COB LED modules have so far been known as LED modules (see JP Pub. No. 2014-170947 (hereinafter referred to as “Document 1”) and JP Pub. No. 2008-140934 (hereinafter referred to as “Document 2”)).
A COB LED module described in Document 1 includes, for example, a resin substrate, LED chips mounted on a first main surface of the resin substrate, metal lines, electrode terminals, a resist (an electric insulation coating), and sealing members formed of resin containing phosphor. The metal lines are patterned on the first main surface of the resin substrate. Examples of metal material of the metal lines include copper and the like. The resist is formed over the whole of the first main surface of the resin substrate except for metal lines on junctions of the LED chips and the electrode terminals. The resist is formed of white resin material.
A COB LED module described in Document 2 includes a device substrate, a white reflection layer deposited on the whole surface of the device substrate, a circuit pattern formed on the reflection layer, and LED chips. The LED chips are adhered to the white reflection layer with an adhesion layer. The circuit pattern is formed of copper foil.
In a mount substrate which allows LED chips to be mounted on, and a COB LED module with the same, there is a concern about reduction in reliability owing to oxidation or corrosion of copper in a case where components formed of copper are included like Documents 1 and 2.